Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing. However, there are cases of aggressive prostate cancers. The cancer cells may metastasize from the prostate to other parts of the body, particularly to the bones and lymph nodes. Prostate cancer may cause pain, difficulty in urinating, problems during sexual intercourse, or erectile dysfunction. Other symptoms can potentially develop during later stages of the disease.
Rates of detection of prostate cancers vary widely across the world, with detection rates in south and east Asia being lower than those in Europe, and especially in the United States. Prostate cancer tends to develop in men over the age of fifty and, although it is one of the most prevalent types of cancer in men, many never have symptoms or undergo therapy for prostate cancer, and eventually die of other causes. Further, treatment of prostate cancer may do more harm to the subject than the prostate cancer itself. Prostate specific antigen (PSA) screening has led to a significant rise in the number of men diagnosed with prostate cancer with an associated increase in potentially unnecessary biopsies preformed. Despite its limitations, including a positive predictive value of only 25-40%, PSA remains the only generally accepted biomarker for prostate cancer.
Prostate cancer is, in most cases, slow-growing and symptom-free. Moreover, since men with the condition are typically older, they often die of causes unrelated to the prostate cancer, such as heart/circulatory disease, pneumonia, other unrelated cancers, or old age. On the other hand, the more aggressive prostate cancers account for more cancer-related deaths among men in the United States than any other cancer except lung cancer.
About two-thirds of prostate cancer cases are slow growing, whereas the other third are more aggressive and fast developing. It is important to be able to distinguish between aggressive and non-aggressive forms of the disease, and further, to distinguish prostate cancer from benign prostate hyperplasia (BPH). Commonly used screening tests, e.g., for prostate specific antigen (PSA) cannot distinguish between prostate cancer and BPH.
Filamin A (FLNA) (also known as FLN-A, FLN1, ABP-280, OPD1, OPD2, Endothelial Actin-Binding Protein, CVD1, FMD, MNS, NHBP, XLVD, XMVD, Actin Binding Protein 280, Alpha-Filamin, Filamin-1, Filamin-A—each of which may appear herein and are considered equivalent terms as used herein) is a 280-kD protein that is thought to crosslink actin filaments into orthogonal networks in cortical cytoplasm. The large molecular-weight protein also participates in the anchoring of membrane proteins to the actin cytoskeleton. FLNA has previously been associated with various cancers.
There remains a need for markers and methods that can be used for the diagnosis, monitoring or prognosis of prostate cancer.